Development of numerical simulation method to evaluate heat transfer of fuel debris in air cooling, 7; Effect of porous internal structure of fuel debris on thermal behavior in PCV

Uesawa, Shinichiro  ; Ono, Ayako ; Yamashita, Susumu   ; Sano, Yoshihiko*; Yoshida, Hiroyuki  

To evaluate the thermal behavior of fuel debris of porous media in primary containment vessels (PCVs) of TEPCO's Fukushima Daiichi nuclear power station for air cooling, JAEA has developed a numerical simulation method using JUPITER code with porous medium models. In this presentation, we report the numerical simulation results of the thermal behavior in the PCV considering three porous structures of fuel debris, such as bubble dispersion, truss structure, and particle packed bed types. The results showed the temperature of the fuel debris was different for each model. It is important to understand the porous structure of the fuel debris for the thermal behavior because the structure has a strong effect on it.